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US5373121A - Method and apparatus for saving electrical energy in an hydraulic elevator drive - Google Patents

Method and apparatus for saving electrical energy in an hydraulic elevator drive Download PDF

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Publication number
US5373121A
US5373121A US08/026,545 US2654593A US5373121A US 5373121 A US5373121 A US 5373121A US 2654593 A US2654593 A US 2654593A US 5373121 A US5373121 A US 5373121A
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Prior art keywords
hydraulic pump
elevator car
cylinder
piston
fluid
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Expired - Lifetime
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US08/026,545
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English (en)
Inventor
Heinz-Dieter Nagel
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Inventio AG
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Inventio AG
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
    • B66B1/00—Control systems of elevators in general
    • B66B1/24—Control systems with regulation, i.e. with retroactive action, for influencing travelling speed, acceleration, or deceleration
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B50/00—Energy efficient technologies in elevators, escalators and moving walkways, e.g. energy saving or recuperation technologies

Definitions

  • the present invention relates generally to an hydraulic drive for elevators and, in particular, to a method and apparatus for reducing the electrical energy required to drive an hydraulic drive pump in an elevator system.
  • a maximum carrying capacity and a speed of travel in the upward direction are selected for the elevator car.
  • a maximum power requirement "N” is calculated by the formula:
  • the maximum power of the drive is utilized only when the elevator car is loaded to the full carrying capacity. For smaller loads, the drive operates with poorer efficiency and thus with relatively high energy consumption.
  • An hydraulic elevator having relatively low energy consumption is shown in the German patent document DE-OS 40 34 666.
  • This elevator is driven by an inverter energy source and includes a main cylinder with a piston connected to an elevator car and an auxiliary or balancing cylinder with a fixed balancing weight and a selectable balancing weight.
  • the cylinders are connected together by an hydraulic pump.
  • the fixed balancing weight corresponds normally to the weight of the elevator car, while the selectable balancing weight corresponds to approximately one half the maximum load in the elevator car.
  • the design of the size of the drive thus depends on the difference between the loading of the balancing cylinder and the main cylinder.
  • the output power during downward travel without a load is calculated by the formula:
  • N is the output or driving power
  • A is the mass of the car
  • B is the mass of the piston
  • W is the mass of the maximum car load
  • w/2 is the mass of one half of the car load
  • v is the lifting speed.
  • a disadvantage of this hydraulic elevator is that an additional auxiliary cylinder with a fixed and a selectable balancing weight, the necessary connecting line and a relatively expensive inverter energy source are required.
  • the present invention concerns a method and an apparatus for operating an hydraulic elevator utilizing a constant output power drive to reduce the amount of electrical energy required by the drive.
  • An electrical motor driven hydraulic pump draws fluid from a reservoir and pumps the fluid through a main line and a control valve into a cylinder of a piston-cylinder unit connected to an elevator car during upward travel of the car. During downward travel of the car, the fluid flows from the cylinder through the control valve back into the reservoir.
  • the invention is based on the task of providing a method and a device for the saving of electrical energy for the drive of an hydraulic elevator, which drive operates with practically constant energy requirements and with good efficiency during upward travel of the elevator car.
  • the nominal travel speed for the car is selected for that load which, according to experience, occurs most frequently.
  • the typical load may be two persons such that a greater travel speed is achieved when the load is less and a lesser travel speed is achieved for a full load.
  • the speed is regulated by a valve in dependence on the loading such that the travel speed is increased for greater loading.
  • such a drive system can be smaller than a drive system which operates at a constant nominal travel speed for each load.
  • the method for reducing the power required to drive an hydraulic elevator system includes the steps of determining a load of an elevator car connected to a piston-cylinder unit during upward travel of the elevator car by sensing a fluid pressure value of fluid being supplied to a cylinder of the piston-cylinder unit, generating a control signal proportional to the sensed fluid pressure value, and controlling a pump supplying fluid to the cylinder in response to the control signal to maintain a constant output power from the piston-cylinder unit whereby as the load of the elevator car changes, a speed of travel of the elevator car is changed.
  • the pump is controlled by regulating a displacement volume of the pump in an inverse relationship to the load of the elevator car.
  • FIG. 1 is a schematic block diagram of an hydraulic drive system for an elevator utilizing a variable displacement pump
  • FIG. 2 is a schematic block diagram of an hydraulic drive system for an elevator utilizing a positive displacement pump.
  • an hydraulic elevator drive system C having a piston-cylinder unit 1 which includes a piston 2 movable up and down in a generally vertically extending cylinder 3.
  • a piston rod 4 is attached to an upper surface of the piston 2 and extends through an upper end of the cylinder 3 for moving an elevator car (not shown).
  • the cylinder 3 has an opening 3a formed adjacent a lower end thereof which opening is connected by a supply line 5 with an outlet port 6a of a control or lowering valve 6.
  • the port 6a is normally closed as shown.
  • the control valve 6 can be actuated to a setting A for the upward operation of the piston 2 and to a setting B for the downward operation of the piston.
  • An inlet port 6b of the control valve 6 is connected to an outlet port 8a of a variable displacement pump 8 by a main line 7.
  • An inlet port 8b of the pump 8 is connected to an hydraulic fluid reservoir 9 by an inlet line 10.
  • the pump 8 is driven by an electrical motor 11 mechanically coupled to the pump.
  • the main line 7 is connected to one end of a sensing line 12 having an opposite end connected through a flow restrictor or throttle 13 to an inlet of a pressure regulating valve 14.
  • the fluid pressure in the cylinder 3 is sensed by the control line 12 and a fluid control signal is applied to the valve 14
  • the valve 14 has an outlet connected to the pump 8 for regulating the displacement volume at the outlet port 8a in response to the control signal.
  • FIG. 2 there is shown an alternate embodiment hydraulic elevator drive system D having a piston-cylinder unit 21 which includes a piston 22 movable up and down in a generally vertically extending cylinder 23.
  • a piston rod 24 is attached to an upper surface of the piston 22 and extends through an upper end of the cylinder 23.
  • the cylinder 23 has an opening 23a adjacent a lower end thereof connected to an outlet port 26a of a control valve 26 by a supply line 25.
  • the outlet port 26a is normally closed as shown and the valve 26 can be actuated to a setting A for the upward movement of the piston 22 and to a setting B for the downward movement of the piston 22.
  • An inlet port 26b of the control valve 26 is connected to an outlet port 28a of a positive displacement pump 28 by a main line 27.
  • An inlet port 28b of the pump is connected to an hydraulic fluid reservoir 29 by an inlet line 30.
  • the positive displacement pump 28 is driven by an electrical motor 31 mechanically coupled to the pump.
  • the motor 31 is electrically connected to a frequency transformer 32 which regulates the speed of the motor steplessly in dependence on the loading of the pump 28.
  • a pressure measurement transducer 33 is connected by a sensing line 34 to the supply line 25.
  • the pressure measurement transducer 33 generates a control signal proportional to the fluid pressure sensed in the line 25 over an electrical line 35 connected between the transducer 33 and an amplifier 36.
  • the amplifier 36 is electrically connected to the frequency transformer 32 which responds to the control signal generated by the amplifier 36 by controlling the speed of the motor 31.
  • an elevator car (not shown) is moved upwardly by the piston rod 4 as hydraulic fluid is urged into the cylinder 3 of the piston-cylinder unit 1.
  • the control valve 6 is switched to the setting A to provide a first flow path and hydraulic fluid is drawn from the reservoir 9 by the pump 8 and is forced under pressure through the control valve 6 by way of the line 5 into the opening 3a thereby moving the piston 2 and the piston rod 4 in an upward direction.
  • the variable displacement pump 8 is controlled by the pressure regulating valve 14 in correspondence with the fluid pressure in the cylinder 3 so that, for constant driving power, the displacement volume of the pump 8 results in a speed of travel of the elevator car in the upward direction which corresponds to the load prevailing in the elevator car.
  • the pressure in the cylinder 3 rises and the pump 8 is adjusted so that, for practically constant driving power, the displacement volume of the adjustable pump and, the speed of travel of the elevator car in the upward direction, both decrease.
  • the elevator car (not shown) is moved upwardly by the piston rod 24 as hydraulic fluid is urged into the cylinder 23 of the piston-cylinder unit 21.
  • the control valve 26 is switched to the setting A to provide a first flow path and hydraulic fluid is drawn from the reservoir 29 by the positive displacement pump 28 driven by the electrical motor 31.
  • the electrical motor 31 is controlled by the frequency transformer 32 at a frequency dependent on the loading of the elevator car.
  • the pressure measurement transducer 33 senses fluid pressure prevailing in the cylinder 23 in correspondence with the load present in the elevator car and converts this pressure measurement by way of the amplifier 36 and the frequency transformer 32 into a corresponding frequency.
  • the rotational speed of the drive motor 31 for driving the positive displacement pump 28 depends upon the frequency of the electrical power supplied from the transformer 32 in that a lower frequency is generated for greater loading of the elevator car represented by high pressure in the cylinder 23, and the positive displacement pump 28 is driven at a lower rotational speed by the drive motor 31.
  • the displacement volume of the positive-displacement pump 28 thereby is reduced for practically constant driving power and the speed of travel of the elevator car in the upward direction decreases.
  • the speed of travel of the elevator car in the downward direction is regulated by the control valves 6 and 26 respectively, which valves are switched to the setting B to provide a second flow path such that the lowering speed of the elevator car is increased for higher loads.
  • the control valve 6 has an outlet port 6c which is connected to the port 6a in the B setting for fluid flow from the cylinder 3 to a reservoir 15 connected to the port 6c.
  • the control valve 26 has an outlet port 26c which is connected to the port 26a in the B setting for fluid flow from the cylinder 23 to a reservoir 37 connected to the port 26c.
  • the reservoirs 15 and 37 can be the reservoirs 9 and 29 respectively.
  • each of the drive systems C and D shown in the FIGS. 1 and 2 respectively, to provide stepped travel speeds.
  • a variable displacement pump with two or more different constant speeds can be used in place of the variable displacement pump 8 shown in the FIG. 1.
  • a positive displacement pump with a frequency regulated drive motor having two or more fixed rotational speed steps for different loads can be used in place of the pump 28 shown in the FIG. 2.
  • the nominal upward travel speed for the elevator car is selected for that load which, according to experience, occurs most frequently.
  • the typical load may be two persons such that a greater travel speed is achieved when the load is less and a lesser travel speed is achieved for a full load.
  • the speed is regulated by a valve in dependence on the loading such that the travel speed is increased for greater loading.
  • the drive system according to the present invention can be smaller than a drive system which operates at a constant nominal travel speed for each load.

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  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Elevator Control (AREA)
  • Types And Forms Of Lifts (AREA)
  • Forklifts And Lifting Vehicles (AREA)
US08/026,545 1992-03-04 1993-03-04 Method and apparatus for saving electrical energy in an hydraulic elevator drive Expired - Lifetime US5373121A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH67092 1992-03-04
CH00670/92 1992-03-04

Publications (1)

Publication Number Publication Date
US5373121A true US5373121A (en) 1994-12-13

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US08/026,545 Expired - Lifetime US5373121A (en) 1992-03-04 1993-03-04 Method and apparatus for saving electrical energy in an hydraulic elevator drive

Country Status (16)

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US (1) US5373121A (de)
EP (1) EP0558934B2 (de)
JP (1) JPH05338928A (de)
CN (1) CN1026813C (de)
AT (1) ATE141573T1 (de)
AU (1) AU660068B2 (de)
CA (1) CA2088893C (de)
CZ (1) CZ286024B6 (de)
DE (1) DE59303462D1 (de)
DK (1) DK0558934T4 (de)
ES (1) ES2093289T5 (de)
FI (1) FI112791B (de)
HU (1) HU212112B (de)
MX (1) MX9301151A (de)
NO (1) NO930756L (de)
SK (1) SK279308B6 (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19511591A1 (de) * 1995-03-29 1996-10-17 Jungheinrich Ag Verfahren zur Bestimmung der Last eines Flurförderzeugs
US5818185A (en) * 1994-11-07 1998-10-06 Mannesmann Aktiengesellschaft Process and device for monitoring and controlling the speed of rotation of an electric drive with frequency converter for hoisting gears
US6089353A (en) * 1996-08-16 2000-07-18 Bt Prime Mover, Inc. Material handling vehicle having a stability support
US6142259A (en) * 1997-02-06 2000-11-07 Bucher-Guyer Ag Method and device for controlling a hydraulic lift
US6505711B1 (en) * 1999-08-25 2003-01-14 Bucher Hydraulics Ag Hydraulic elevator, comprising a pressure accumulator which acts as a counterweight and a method for controlling and regulating an elevator of this type
US20040182234A1 (en) * 2002-12-20 2004-09-23 Dorma Gmbh + Co. Kg Electrohydraulic servo door drive for operating a door, a window, etc.
US20090099714A1 (en) * 2007-10-12 2009-04-16 Ajith Kuttannair Kumar System and method for dynamically determining a force applied through a rail vehicle axle
US20100319568A1 (en) * 2007-10-12 2010-12-23 Ajith Kuttannair Kumar System and method for dynamically affecting a force applied through a rail vehicle axle

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4335403C1 (de) * 1993-10-18 1994-12-15 Karl Hehl Hydraulikeinrichtung
JP2004003612A (ja) * 2002-04-09 2004-01-08 Komatsu Ltd シリンダ駆動システム及びそのエネルギ回生方法
DE102012106031B3 (de) * 2012-07-05 2013-07-11 Römer Fördertechnik GmbH Elektrohydraulisches Hubgerät sowie Verfahren zur Steuerung des elektrohydraulischen Hubgerätes
CN103267038B (zh) * 2013-05-09 2017-02-08 洛阳理工学院 一种控制多台升降台的液压控制回路
CN104481947A (zh) * 2014-12-08 2015-04-01 西南铝业（集团）有限责任公司 倾翻炉共用液压控制系统
CN104627837B (zh) * 2015-02-11 2016-06-08 河海大学常州校区 一种行车精准吊装机具
CN104609315B (zh) * 2015-02-11 2016-06-29 河海大学常州校区 一种行车精准吊装机具

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH465805A (de) * 1967-01-06 1968-11-30 Leipzig Inst Foerdertech Hydrostatischer Antrieb mit Gegengewichts-System, insbesondere für Aufzüge
US3762165A (en) * 1970-12-07 1973-10-02 Hitachi Ltd Hydraulic elevator apparatus
US3842943A (en) * 1972-03-15 1974-10-22 Hitachi Ltd Hydraulic elevator
US4199943A (en) * 1976-12-24 1980-04-29 Eimco (Great Britain) Limited Fluid transmission circuit
JPS60246412A (ja) * 1984-05-21 1985-12-06 Mitsubishi Electric Corp 運搬装置
NL8701922A (nl) * 1987-08-14 1989-03-01 Jacobus Leonardus Saam Energiezuinige hydraulische liftaandrijving met regelbare motor voor beide rijrichtingen (zonder stuurblok).
US5014823A (en) * 1987-11-04 1991-05-14 Kone Elevator Gmbh Apparatus for improving the performance of a motor-controlled hydraulic elevator
DE4034666A1 (de) * 1990-04-25 1991-10-31 Kaisei Kogyo Kk Hydraulischer aufzug mit geringem energieverbrauch
US5243154A (en) * 1990-10-16 1993-09-07 Mitsubishi Denki Kabushiki Kaisha Apparatus for controlling a hydraulic elevator

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1184055B (de) † 1959-05-27 1964-12-23 Kaemper Motoren G M B H Hydraulisch angetriebenes Hubwerk
DE2658928A1 (de) † 1976-12-24 1978-07-06 Beringer Hydraulik Gmbh Hydraulische steuerung
JPH03159879A (ja) † 1989-11-20 1991-07-09 Toyota Autom Loom Works Ltd 産業車両の荷役制御装置

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH465805A (de) * 1967-01-06 1968-11-30 Leipzig Inst Foerdertech Hydrostatischer Antrieb mit Gegengewichts-System, insbesondere für Aufzüge
US3762165A (en) * 1970-12-07 1973-10-02 Hitachi Ltd Hydraulic elevator apparatus
US3842943A (en) * 1972-03-15 1974-10-22 Hitachi Ltd Hydraulic elevator
US4199943A (en) * 1976-12-24 1980-04-29 Eimco (Great Britain) Limited Fluid transmission circuit
JPS60246412A (ja) * 1984-05-21 1985-12-06 Mitsubishi Electric Corp 運搬装置
NL8701922A (nl) * 1987-08-14 1989-03-01 Jacobus Leonardus Saam Energiezuinige hydraulische liftaandrijving met regelbare motor voor beide rijrichtingen (zonder stuurblok).
US5014823A (en) * 1987-11-04 1991-05-14 Kone Elevator Gmbh Apparatus for improving the performance of a motor-controlled hydraulic elevator
US5048644A (en) * 1987-11-04 1991-09-17 Kone Oy Method for improving the performance of a motor controlled hydraulic elevator
DE4034666A1 (de) * 1990-04-25 1991-10-31 Kaisei Kogyo Kk Hydraulischer aufzug mit geringem energieverbrauch
US5243154A (en) * 1990-10-16 1993-09-07 Mitsubishi Denki Kabushiki Kaisha Apparatus for controlling a hydraulic elevator

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5818185A (en) * 1994-11-07 1998-10-06 Mannesmann Aktiengesellschaft Process and device for monitoring and controlling the speed of rotation of an electric drive with frequency converter for hoisting gears
DE19511591A1 (de) * 1995-03-29 1996-10-17 Jungheinrich Ag Verfahren zur Bestimmung der Last eines Flurförderzeugs
US6089353A (en) * 1996-08-16 2000-07-18 Bt Prime Mover, Inc. Material handling vehicle having a stability support
US6142259A (en) * 1997-02-06 2000-11-07 Bucher-Guyer Ag Method and device for controlling a hydraulic lift
US6505711B1 (en) * 1999-08-25 2003-01-14 Bucher Hydraulics Ag Hydraulic elevator, comprising a pressure accumulator which acts as a counterweight and a method for controlling and regulating an elevator of this type
US20040182234A1 (en) * 2002-12-20 2004-09-23 Dorma Gmbh + Co. Kg Electrohydraulic servo door drive for operating a door, a window, etc.
US6978609B2 (en) * 2002-12-20 2005-12-27 Dorma Gmbh + Co. Kg Electrohydraulic servo door drive for operating a door, a window, etc.
US20090099714A1 (en) * 2007-10-12 2009-04-16 Ajith Kuttannair Kumar System and method for dynamically determining a force applied through a rail vehicle axle
US20100319568A1 (en) * 2007-10-12 2010-12-23 Ajith Kuttannair Kumar System and method for dynamically affecting a force applied through a rail vehicle axle
US8371233B2 (en) * 2007-10-12 2013-02-12 General Electric Company System and method for dynamically affecting a force applied through a rail vehicle axle

Also Published As

Publication number Publication date
NO930756L (no) 1993-09-06
DK0558934T4 (da) 2001-03-05
DE59303462D1 (de) 1996-09-26
FI930918A (fi) 1993-09-05
CA2088893A1 (en) 1993-09-05
CZ286024B6 (cs) 1999-12-15
EP0558934B2 (de) 2000-12-06
EP0558934B1 (de) 1996-08-21
AU3392093A (en) 1993-09-09
NO930756D0 (no) 1993-03-02
CZ17893A3 (en) 1993-11-17
MX9301151A (es) 1993-09-01
HU212112B (en) 1996-02-28
CA2088893C (en) 2003-11-25
HUT64610A (en) 1994-01-28
FI930918A0 (fi) 1993-03-02
SK10393A3 (en) 1993-10-06
ES2093289T5 (es) 2001-04-01
CN1077256A (zh) 1993-10-13
EP0558934A1 (de) 1993-09-08
AU660068B2 (en) 1995-06-08
DK0558934T3 (da) 1996-12-23
SK279308B6 (sk) 1998-09-09
ES2093289T3 (es) 1996-12-16
HU9300433D0 (en) 1993-05-28
FI112791B (fi) 2004-01-15
JPH05338928A (ja) 1993-12-21
ATE141573T1 (de) 1996-09-15
CN1026813C (zh) 1994-11-30

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